Radio signaling apparatus



Aug. 11, 1925.

G. H. CLARK RADIO SIGNALING APPARATUS Filed Feb. 23, 1921 Patented Aug. 11, 1925 UNITED STATES GEORGE E. CLARK, OF BROOKLYN, NEW YORK, ASSIGNOR TO nnmo conPonA TION OF AMERICA, A CORPORATION OF DELAWARE.

RADIO SIGNALING APPARATUS.

Application filed February as, 1921. Serial No. 447,017.

To all whom it may concern:

Be it known that I, GEORGE H. CLARK, a citizen of the United States, and a resident of Brooklyn, New York, have invented certain new and useful Improvements in Radio Signaling Apparatus, of which the following is a specification, accompanied by drawings.

This invention relates to improvements in signaling with radio telegraph transmitters of the arc generator type.

Systems of this type utilize an arc cooperatively associated with the antenna for producing high frequency continuous oscillations therein. For signal production vari: ous methods have been employed. One of these, consists in changing the wave length of the radiation which has been done in various ways. This is undesirable on account of the radiation of interfering frequencies which prevents others from. utilizing this frequency for signaling. Another system, designed to eliminate this disadvantage, damps the radiated wave by the use of a non-radiating absorption circuit to which the are is diverted in the periods between the dots and dashes. Dilliculty is encountered with this system in damping out the radiation sufficiently.

.The object of the present invention is to provide a simplified system of signaling with are geneartors which is free from the objectionable features mentioned.

The novel features which I believe to be characteristic of'niy invention are set forth with particularity in the appended claims, the invention itself, however, both as to its construction and mode of operation, together with further objects and advantages thereof will best be understood by reference to the following-description taken in connection with the accompanying drawing in which the single figure is a diagrammatic representation of an arrangement which may be employed in carrying my invention into effect.

In the drawing 1 represents diagrammatically an antenna having the usual inductance 2. An arc generator 4 is cooperatively connected thereto, for example by connecting electrodes 5 and 6 of the arc in series therewith and to ground at 3. The are generator preferably consists of an adjustable copper electrode 5 and a carbon electrode 6 projecting in an arc chamber 7 supplied with hydrogen vapor b feeding water, alcohol or other suitable liquid to the chamber from the reservoir 8. The electrodes are supplied with energy for producing the arc and the high frequency oscillations from a direct current generator 9. To render the are unstable so as to be in condition to generate oscillations a winding 10 of an electro magnet is connected in series with the electrodes 5, 6 and generator 9, and is provided with an iron core 11 projecting into the arc chamber 7 into a position to influence the arc.

has been set forth to facilitate understanding of the invention.

In accordance with my improvement, the are is intermittently formed in synchronism with the movements of the signaling key preferably by intermittently short circuiting by moving the electrodes substantially into contact with each other. In the embodiment shown diagrammatically this is done by connecting the carbon electrode holder 11 to the armature 12-of a solenoid 13, the winding of which is connected in series with the signaling key 14, and a battery 15. Whenever the key 14 is depressed the carbon electrode is separated from the fixed electrode against the action of spring 12 to start the are which simultaneously causes the generation of high frequency oscillations in the antenna. When the key is open the electrodes will be moved into contact by the spring 12 and thus short circuitcd so that no oscillations or antenna radiation will occur.

It is desirable to provide means for preventing the generator from being overloaded when the electrodes are short circuited without disconnecting the generator from the arc in order to assure immediate starta ing of the are. In the drawing an arrangement for this purpose is illustrated in which a loading coil 16, preferably a resistance unit of suitable value, is inserted in the arm circuit when the signaling key is open and short circuited when the key is closed. In

The general construction of the arc generator described, although well known,

the form shown, this is accomplished by" movement of the electrodes practically into Contact to produce short cireuiting, I may also move the electrodes in such manner that the length of the are is substantially varied Without actually extinguishing by short circuiting the arc. The movement, however, should be sui'licient to almost entirely suppress the generation of oscillations and radiation of eleetro-magnetic waves.

It will be app rent that in signaling in the manner set forth that only one wave length is radiated. The radiation only occurs when the signal key is operated for production of signal although the device is adapted to respond quickly to movements of the telegraph key corresponding to the dots and dashes of the signal as the arc circuit is closed at all times. As the are is only formed during the dots and dashes the cooling problem is considerably simplified.

Having described my invention What I claim is 1. The method of signaling with a contin uous Wave radio telegraph transmitter of the are type which consists in maintaining the electrodes of the are generator in contact to suppress the arc during non-signaling periods, and withdrawing the electrodes to produce the are at the beginning of each signaling period.

2. The method of signaling with a continuous Wave radio telegraph transmitter of the arc type which consists in maintaining the electrodes of the are substantially in contact to prevent the formation of the are during non-signaling periods, and separating said electrodes substantially in synchronism with the beginning of signaling periods to cause production of the are.

3. The method of signaling with a continuous wave radio telegraph transmitter of the arc generator type, which consists in intermittently substantially short circuiting the electrodes of in synchronism with the force producing the signal to suppress the generation of oscillations.

4:. The method of signaling with a continuous wave radio telegraph transmitter of the arc generator type, which consists in substantially short circuiting the electrodes of the signaling are generator in synchronism with the dots and dashes of the signals to intermittently suppress the generation of oscillations.

5. The method of signaling with a continuous Wave radio telegraph transmitter of the are type which consists in maintaining a conductive connection between the arc-form ing electrodes during non-signaling periods and interrupting such connection substantially in synchronism with signaling periods.

6. The method of signalingwitha continuous wave radio telegraph transmitter of the are generator type which consists in the signaling are generator to said antenna circuit and maintaining a conductive connection between the arc-forming electrodes and maintaining a suitable resistance in circuit with said electrodes durin non-signaling periods and interrupting sai' conductive connection and removing said resistance substantially in synchronism with signaling periods to produce the arc.

7. In an arc converter for continuous wave radio signaling, a pair of electrodes adapted to be separated to form a signaling are, and means for intermittently moving said electrodes together .in synchronism with the signaling force to suppress the production of oscillations by extinguishing the are. p

8. In an arc converter for continuous wave radio telegraphic signaling, in combination,

a pair of electrodes adapted to form a signaling are for the production of oscillations, and a signaling key cooperatin therewith, said electrodes being relative y movable toward each other in synchronism with the movements of the signaling key to intermittently substantially short circuit the signaling'arc and said electrodes being maintained substantially in contact during nonsignaling periods.

9. u an arc converter for continuous wave radio telegraphic signaling, in combination, a pair-of electrodes normally substantially short circuited, a signaling key and means cooperative therewith for separating the electrodes for forming the signaling are and producing oscillations.

10. In an arc converter for continuous Wave radio telegraphic si naling, in combination, a pair of electrod es normally substantially short circuited, a generator connected to the electrodes, a loading coil for the generator, a signaling key and means cooperating therewith for separating the electrodes and simultaneously short circuiting the loading coil for the production of oscillations.

11. In an arc converter for continuous wave radio signalin signalin means, a fixed electrode and a longitudina y movable electrode adapted to form a signaling are, and means for moving said second electrode i to substantially short circuit the are, said means being operated in synchronism with the signaling means and maintaining said electrodes substantially short-circuited during non-signaling periods.

12. In a continuous wave are transmitting system, the combination of an antenna circuit, comprising inductance, an arc converter having one electrode conductively connected having the other electrode connectedto ground, a signaling key, and means controlled by said signaling key for maintaining a conductive connection between said electrodesdurin non-signaling periods and for interrupting said connection during signaling periods.

13. In a continuous Wave arc transmitting system, the combination of an antenna c1r- I cuit comprising an inductance, an are converter having one electrode conductively connected to said antenna circuit and having the other electrode connected to ground, a generator for energizing said arc, a resist-ance associated with said generator circuit, a signaling key, means controlled by said signaling key for simultaneously main- GEORGE H. CLARK. 

